CHARLOTTE, N.C. — NAPA Auto Parts said Thursday it is dropping Michael Waltrip Racing at the end of the year in the fallout of the team’s attempt to manipulate a race to get Martin Truex Jr. into NASCAR’s version of the playoffs.

Napa is Truex’s primary sponsor and in the first year of a three-year extension announced last August. The deal ran through the 2015 season.

“NAPA believes in fair play and does not condone actions such as those that led to the penalties assessed by NASCAR,” NAPA said in a statement. “We remain supportive of the millions of NASCAR fans and will evaluate our future position in motorsports.”

The company issued a harsh rebuke of MWR last week after NASCAR sanctioned the organization for its shenanigans in the Sept. 7 race at Richmond. MWR was punished for deliberately manipulating the outcome of the race in an attempt to get Truex into the 12-driver Chase for the Sprint Cup championship field.

NASCAR took the unprecedented step of kicking Truex out of the Chase in favor of Ryan Newman, who would have made it into the field instead of Truex before the MWR manipulations began with seven laps remaining at Richmond. MWR was also fined $300,000, general manager Ty Norris was suspended indefinitely and all three crew chiefs for its drivers were placed on probation for the rest of the year.

The penalties levied against MWR led to a larger NASCAR investigation that uncovered at least one other case of race manipulation. NASCAR was then forced to expand the Chase field to 13 drivers to include Jeff Gordon and issue new rules banning digital radios and more than one team member per car on the spotter stand.

NASCAR Chairman Brian France also ordered all competitors to give 100 percent at all times in an ethics meeting in which it was made clear attempts to artificially alter the outcome of races would be prohibited.

Although it was made clear that MWR was not alone in its actions, NAPA was not pleased with MWR’s involvement and decided to end a relationship with Waltrip that dates back to 2001. NAPA was sponsor for Waltrip for both of his Daytona 500-winning cars and moved with him when he formed Michael Waltrip Racing in 2007. The company took over sponsorship of Truex when he joined MWR in 2010 and as Waltrip’s replacement.

This is the second scandal NAPA has been through with Waltrip, who was found to have a fuel additive in his engine in his debut race, the 2007 Daytona 500.

NASCAR docked the team 100 points, ejected crew chief David Hyder and executive Bobby Kennedy and fined Hyder $100,000 in one of the biggest cheating scandals ever at the Daytona 500. It was also Toyota’s debut race. Waltrip had a miserable season that year, failing to qualify for 20 races with NAPA as his sponsor and nearly going bankrupt.

He recovered, in large part due to the rescue of MWR co-owner Rob Kauffman, who pumped in much-needed cash and brought stability and accountability to the organization.

NAPA won four races with Waltrip, stayed on when Truex took over the car, and his victory this June at Sonoma was its first with him since he began driving the No. 56. Truex did qualify for the Chase with NAPA last season, finishing 11th in points, and was in contention for the final Chase wild card berth at Richmond while driving with a broken wrist.

The loss of a primary sponsor, particularly with only nine races left in the season, will be a crippling blow to the Waltrip organization. It will be a tremendous challenge to quickly replace the money, estimated at least $15 million a year, because NAPA is a rare sponsor that covers that entire 36-race Sprint Cup schedule.

Should MWR not secure sponsorship to replace NAPA, it could lead to layoffs of close to 100 employees and the possible shuttering of Truex’s team. Truex could be out of job, as well.

One last-ditch solution could be a partnership with Furniture Row Racing, which has twice been spurned by drivers Kurt Busch, who turned down an extension, and Juan Pablo Montoya, who took an offer to drive for Roger Penske in IndyCar over replacing Busch. Furniture Row had tried during the summer to defect to Toyota, only to learn the manufacturer didn’t have the space to accommodate another team. An alliance with MWR could get Furniture Row in the Toyota family and be a potential landing spot for Truex, should Waltrip fail to figure out another solution to save his third car.

MWR also fields cars for Clint Bowyer and Brian Vickers, the two drivers who actively participated in the manipulations at Richmond to get Truex into the Chase. Bowyer spun with seven laps remaining to bring out a caution that prevented Newman from winning the race.